Patent GB-1202275-A (GB)
Title: Improved automated press for installing fasteners in a workpiece
IPC: B21J15/02
Filed: 1967-10-17
Abstract: 1,202,275. Inserting fasteners in workpieces. PENN ENG. & MFG. CORP. 17 Oct., 1967 [8 March, 1967], No. 47313/67. Heading B3U. A press for installing fasteners, e.g. nuts, studs in a workpiece comprises a punch assembly 22 and an anvil assembly 24 carried by a frame 12, first solenoid controlled hydraulic and pneumatic means for advancing and retracting the punch assembly 22 with a first force, and second solenoid controlled hydraulic and pneumatic means for applying a second, higher force to the punch assembly during the end portion of its advance. The nuts are fed down a feed track 19 and along a groove 870, Fig. 20, of a gate 162 so that the end nut is restrained above a slot 859b by a spring-biased finger 872. The cycle is initiated by closing a foot switch to energize a solenoid 59, Fig. 2, whereby a valve 60 is actuated so that air from a low-pressure regulator 54 forces oil from a tank 61 into an hydraulic cylinder 66 to force the punch ram 150 downwards. The nut in the gate 162 is thereby engaged by a spring 873, Fig. 10, on a punch pilot 164 whereupon a solenoid 57 is energized by a timer to actuate a valve 56 to cause the air from the regulator 54 to retract a piston 132 which causes the gate 162 to be pivoted out of the way of the advancing punch 166. If the gate 162 has not retracted properly, a leaf-spring 851 is depressed by the advancing punch 166 to actuate a safety switch which deenergizes the solenoid 59 reversing the valve 60 to retract the ram 150. When the anvil nose 875 extending through a hole in the workpiece 874 is engaged by the punch pilot 164, the latter is retracted against the bias of a spring 880 until the punch 166 engages the top of the nut. The nose 875 is thereafter depressed downwardly against the bias of a spring 876 so that the shank of the nut is located in the hole of the workpiece, whereupon solenoids 65 and 72 are energized by a timer to respectively actuate valves 64 and 70. The former causes communication between a booster cylinder 74 and the tank 61 to be blocked and the latter causes high-pressure air to flow from a high-pressure regulator 52 to the booster cylinder 74. Oil under high pressure is caused to flow into the cylinder 66 forcing the ram 150 downwards under a high force to clinch the nut to the workpiece. After a set clinching time, the solenoids 59, 65 and 72 are de-energized, causing the valves 60, 64 and 70 to be actuated thereby returning the apparatus to its initial position. When a nut is to be clinched to the undersurface of a workpiece, a nut with its shank uppermost is transferred by the punch pilot 164 to an anvil nose integral with the anvil. After retracting the punch assembly, the workpiece is placed over the nut and the punch lowered again to contact the workpiece and to clinch the nut thereto. In a modification, for clinching a stud to a workpiece, Fig. 25, a stud is placed by a pusher 920 between the ends of leaf-springs 914 attached to a case 906 through which the punch 907 is slidable. As the ram 150 descends, a stop 940 attached to the case 906 is moved out of engagement with a stop (943) to cause the case 906 to be moved upwardly by springs 910 relative to the punch 907 which thereby contacts the stud head. When the stud engages the anvil nose 946 extending through a hole in the workpiece, the nose 946 is retracted until the case 906 rests upon the workpiece, whereupon the punch 907 clinches the head of the stud so that its upper surface lies flush with the workpiece surface.